With the advent of sophisticated equipment in the electrical and electronic fields, it has become necessary that the components of the various pieces of equipment conform to high standards which are set forth in the specifications for these components. For example, circuit boards which are used in relatively complicated pieces of equipment such as main frame computers, must be of a relatively high standard of quality in order to function in an efficient manner for a longer period of time without deteriorating or breaking down, and thus causing an interruption in the function of the machine. This high quality of material is opposed to pieces of equipment requiring a lower standard of quality such as those used in personal computers, high quality television equipment, radios, etc.
Circuit boards upon which a circuit is etched or implanted usually comprise a laminate which is composed of a synthetic polymeric substance which possesses desirable characteristics such as thermal stability, low coefficient of thermal expansion, dimensional stability, low dielectric constant, solvent resistance, low moisture absorption, etc. and a suitable reinforcement matrix, such as glass, quartz, graphite, Kevlar, etc.
As will hereinafter be shown, it has now been discovered that a semi-interpenetrating polymer network resin may be prepared by admixing a semi-crystalline engineering condensation thermoplastic compound with a poly(vinyl benzyl ether) of a polyphenol. The resulting material will comprise a processable material which contains desirable components, said blend preventing the linear engineering condensation thermoplastic from crystallizing, especially at high cross-linked/linear ratios, inasmuch as the interpenetration will prevent short range stereoregulatity necessary for packing into crystalline lattices. In addition, the presence of the cross-linked poly(vinyl benzyl ether) will serve to reinforce the more ductile engineering condensation thermoplastic.